Sheet item handling and stacking apparatus



Sept. 19, 1967 D. E. KAPLAN SHEET ITEM HANDLING AND STACKING APPARATUS 2Sheets-Sheet 1 Filed Dec. 14, 1964 INVENTOR. DONALD E. KAPLAN AGENTSept. 19, 1967 D E. KAPLAN 3,342,481

SHEET ITEM HANDLING AND STACKING APPARATUS Filed Dec. 14, 1964 2Sheets-Sheet 2 Fig.3

INVENTOR. DONALD E. KAPLAN AGENT United States Patent 3,342,481 SHEETITEM HANDLING AND STACKING APPARATUS Donald E. Kaplan, Philadelphia,Pa., assignor to Burroughs Corporation, Detroit, Mich, a corporation ofMichigan Filed Dec. 14, 1964, Ser. No. 418,071 Claims. (Cl. 271-71) Thepresent invention relates to item handling and stacking apparatus, and,more particularly, although not necessarily exclusively, to itemhandling apparatus for stacking individual items from a constantlymoving stream of items with space between them, moving at a rate of sixper second, into a stacker-hopper without rear-end collisions or itemjams caused by one item impinging or curling against another itemthereby blocking the inflow of succeeding item-s.

Still more particularly, the invention has to do with item stackingapparatus for use with postage mail of letter type and with means forstacking mail of intermixed size, thick- 7,

ness, height and weight by causing the mail to move into a stackinghopper at a relatively high rate of speed.

The sorting of individual sheet items involves the passage of such itemsthrough means for separating the items one from another and maintainingsuch separation until such time as the items have been stacked at aterminal location. Where all of such items are of any single thicknessas sheets of paper or cardboard, etc., stacking can be accomplishedrelatively easy. Where, however, the items vary in both thickness aswell as length, and weight, then the conventional item handlingapparatus fails to provide an efficient means for stacking items in acontinuous flow.

It is an important object therefore of the present invention to providea new and novel and heretofore unknown apparatus for stacking individualitems of varying length, breadth and thickness.

Another object of the invention is to provide means for assuring thateach item entering the stacker-hopper is end registered with a stackingabutment within the hopper.

Still another object of the invention is to provide a unitary means forsimultaneously moving the item into the stacker-hopper and deflectingthe trailing portion of one item out of the way of the leading portionof the next succeeding item thereby to avoid any collision between thetwo items.

In accordance with the foregoing objects and first briefly described,the present invention comprises an item stacker-hopper including acanted input guiding surface terminating adjacent a multi-facetedrotatable element disposed adjacent to a movable stacker-hopper back-upplate. Means is provided adjacent to the guiding surface for directingthe items at high speed into the stacker-hopper. Further, pressuredifferential means is provided adjacent to said guiding surface whereby,as a result of the Bernoulli effect, each incoming item is caused toadhere to and slide over a thin film of air along the canted surfaceduring a major portion of its travel into the stacker-hopper andthereafter to have its trailing edge portion deflected transjversely outof the way of an incoming item thereby to effect an ordered,progressive, consecutive stacking of individual items without attendantrear-end collision or jams 'of the apparatus.

These and other objects and advantages of the present invention willbecome more apparent from a reading of the following description ofapparatus embodying the principles of the present-invention when takenin conjunc- 1 tion with the appended claims and the accompanyingdrawings wherein:

FIGURE 1 is.a top plan view of the present invention; 70

FIGURE 2 is a view taken along the line 2-2 FIGURE 1 of thestacker-hopper;

3,342,481 Patented Sept. 19, 1967 FIGURES 3 through 5 inclusive areviews taken along the line 3-3 of FIGURE 2 illustrating consecutivesteps in the advancement of an item into the stacker-hopper apparatusembodying the present invention.

Referring now to the drawings and particularly to FIGURES 1 and 2thereof, apparatus 10 embodying the present invention is seen tocomprise a rigid platform or base 12 of metal, e.g., aluminum, on whichis diagonally, vertically mounted a relatively thin, rigid,fiat guidanceplate member 14 which is secured to the base 12 by means of an anglebracket 16 mounted thereto by one or more screws 18. The left portion 15of member 14, as viewed in FIGURE 1, is provided with a series ofrectangular apertures 20 disposed in parallel spaced apart relationship,as seen more clearly in FIGURE 2. The rightward end portion 22 of member14 is bent angularly out of the plane of the main portion thereof asindicated and is provided with a plurality of apertures 24, as seen moreclearly in FIGURE 2. A supporting angle bracket or tab 26 secures therightward extension of member 14 to base 12 by means of screw 28. Asecondary vertically disposed guide plate 30, attached to base 12 bymeans of a bracket 32 and screws 34, extends for a short distanceparallel (as seen in FIGURE 1) to the upper left-hand portion of guidemember 14 adjacent to the leftward edge of the row of apertures 20,FIGURE 2.

Extending along the right-hand portion of base 12 and verticallydisposed relative to the base is a follower plate 36 which is rockablyjournalled by means of bearings 38 on a horizontal guide bar 40 securedto the base by means of a vertically disposed bracket 42 and adapted tobe moved slidably to and fro along bar 40. .A biasing member 44 securedto a projecting stud 46 in the journal of the member 36 is adapted tocause the follower 36 to move in the direction of the arrow 48.

Along the left side portion of the base member 12 is mounted avertically disposed plate or wall forming member 50 attached to the baseby means of angle bracket 52 and screws 54. The bracket 50 is disposednormal to the follower plate 36 and includes a portion which projectsinto relatively close proximity with the wall forming member 30. Member50 is provided with an undercut portion 56 for clearance purposes whichwill be explained hereinafter. v

As seen more particularly in FIGURE 2, a vertically extending shaft 58provided with bearing member 60 is attached to the underneath surface ofmember 12 in a suitable manner by means of the flange 62. Shaft 58projects vertically upwardly through an aperture (not shown) provided inmember 12 and carries four parallel spaced apart drive rollers 64 whichare adapted to project slightly into and through apertures 20 with whichthey are associated and into surface contact with a series of four idlerrollers 66 disposed on and rotatable about shaft 68. Two triangularlyshaped rock plates (one top and one bottom) designated 70, pivotallymounted on a shaft 72 attached to the base 12, permit rollers 66 to bearcuately movable via clearance opening 56, toward and away from thedrive rollers 64. A spring 74 biases the rock plates in a direction tobring the idler rollers into contact with the surface of the associatedrollers.

Shaft 58 carries a pulley 76 at its opposite (lower) end over which adrive belt 78 is disposed'so as to engage a pulley 80 secured to shaft82. One end of shaft 82 is 5 provided with a second pulley 84 driven bybelt 86 from a source of rotative torque, such for example, as anelectric driving motor, not shown. Shaft 82 is journalled in bearingmember 88 attached in a suitable manner by flange 90 to the lowerportion of the mounting plate 12 and projects vertically upwardlythrough an opening (not shown) in plate 12. The upper end of shaft 82carries four hexa gonally shaped, spaced apart, beater rollers 92 whichare adapted to project slightly into and through the apertures 24, forpurposes to be explained hereinafter.

Disposed adjacent pinch rollers 64 and 66 is a pressure establishingmeans 94, which includes a rigid block 96 provided with an internalhollow chamber 98 (FIGURES 3-5) and an outlet passage 100 leading to anoutlet orifice 102 which is disposed adjacent an area substantiallymidway between the two centermost apertures of the group of apertures 20(see FIGURE 2) and slightly displaced to the left of the vertical axisof rollers 64 and 66. An inlet pipe or tube 104 enables fluid underpressure such to be introduced into and through member 94. The exitingair from outlet orifice or nozzle 102 provides an aerodynamic conditionhereinafter referred to as the Bernoulli effect.

Apparatus embodying the present invention may be employed for example,as an item stacking hopper in a high speed Post Office mail readersorter. Such apparatus handles letter mail at a rate of six per secondat a velocity of 120 inches per second which effectively produces a20-inch pitch separation between items. Letter mail varies in overallsize, weight, thickness, etc. To the end that each item is forwarded tothe item stacker in orderly progression, with each item following thepreceding item in consecutive order, means is provided for moving theincoming item out of the way of the next succeeding item quickly enoughso: that the succeeding item does not collide with the previous item.

The present invention utilizes the so-called Bernoulli effect asdescribed hereinbelow, in which a relatively high velocity stream ofpressurized fluid, e.g., air is introduced via inlet 104 to nozzle 102adjacent to the rollers 64, and 66, so as to exit from the nozzle in adirection rightwardly (FIGURES 13, 4 and 5) bet-ween the center pair ofrollers 64, FIGURE 2, toward the hopper or stacker area.

A number of dimensions are considered in the structure heretoforedescribed and each is more or less operably associated with the othersto form a useful and eflicient combination. Dimension X refers to thewidth of the stacker-hopper and to the actual item impact area whereinthe mail is to be received and stacked. This dimension must be at leastas Wide as the longest item which is to he handled by the apparatus.Dimension Y is the distance between the axial center of the rollers 92and the registration plate member 42 against which the items finallycome to rest in edge alignment. This dimension must be less than thelength of the shortest item to be handled by the present invention.Dimension Z is the distance an incoming item travels before this itemclears the rear edge of the preceding stacked item. This distance is notfixed but will necessarily vary with the length of the already stackeditemthe shorter the stacked item the longer is this dimension and viceversa.

The present invention, as is seen most clearly in FIG- URES 3 through 5inclusive, locates the uppermost set of rollers so as to project aslight distance into an item channel or guideway 106 formed between themember 14 and member 32. When an item e.g., item 108 passes into thischannel and subsequently is gripped between rollers 64 and 66, it iscaused to move forwardly thereof, that is, ri-ghtward'ly, the lowersurface 110' of the plate 14 and the top surface 112 of the itemtogether form a second very narrow channel 114 through which thepressurized air from the jet or nozzle flows with a relatively highvelocity. The pressure of the air changes with its velocity andtherefore in the narrow channel 114 it is less than that of theatmosphere on the lower side 116 of the item. As a consequence, as longas the letter item is in the grip of the rollers 64-66, the highvelocity air is caused to flow therebetween in a manner such that thehigher atmospheric pressure provides a force F causing the envelope orletter to move along on a thin film of air closely hugging the plate 14during its movement along the lower surface thereof.

This so-called Bernoulli effect continues to cause the item or items tomove as described until the trailing edge 118 of the latter has passedthe outlet nozzle 102 preparatory to the item leaving the bite of therollers 64-66. By this time the item is sufficiently far into thestackerhopper to start to slide over or across the top of the previouslystacked item. Leaving the rollers 64-66, the items forward momentumcarries it toward the hexagonal beater rollers 92.

As the item approaches the rollers 92 it encounters the point oftangency of these wheels in the existing stack of items (i.e., thealternate flats and points of the wheels relative to either the back-upplate 36 or the exposed surface of previously stacked items). Theleading edge of the item is then pinched in that region under thehexagonal rollers. As the item is driven further into the stack area thecombination of the bent portion 22 of plate 14 and the pressure ofback-up plate 36 cause the trailing portion of the item to sweep or bendthrough the angle theta 0 swinging the rear end out of the way of thenext incoming item.

At this point, since the item has passed the wheels 64-66, air from thenozzle 102 is no longer constrained to move between the plate 14 and thetop surface 112 of the item but now passes between the pinch rollers soas to strike the trailing edge 118 of the item with a sufficient forceto aid in moving the item downwardly, FIGURE 2, through the angle theta6 effectively moving the trailing edge of the incoming item out of theway of the succeeding or following item, which is approaching the streamof air. Thus by the time the leading edge of the following itemintersects the axis of the air jet and is received within the bite ofthe pinch rollers 64-66, the original item has landed flat on the pileof items previously stacked and edge aligned (if any), or, fiat on thefollower plate 36 if it is the first item to be moved into thestacker-hopper.

The present apparatus has the additional desirable feature that sinceonly the angled tips of the hexagonal rollers 92 are actually in contactat any particular time with the top surface of the item, there is acontinuously available space between the fiat surface of the hexagonalrollers and the flat surface of the already stacked items into which thesucceeding item may proceed for stacking, edge alignment andregistration against member 42. In this manner it can be seen that highspeed stacking can be accomplished quite readily without the problem ofrear-end collisions between the first and any succeeding item or itemsthat are stacked in the hopper. As the hopper accumulates individualitems, the follower plate 36 is caused to move downwardly in FIGURE 1,or parallel to the bed of the hopper against the constant tension of thebiasing member 44.

A secondary plate member (not shown) disposed parallel to the platemember 36 and operable in substantially similar fashion to this platei.e., arcuately movable about the rod member 40, so as to be insertableinto the stack of items, permits the stack of items to be effectivelyseparated into two parts. As the hopper fills with items the firstfollower member is arcuately moved out of the stack and reinserted atthe head or front thereof thereby making it possible and practical tounload a large number of items from the stacker-hopper during thestacking operation without interferring with the incoming items ornecessitating the shutting down of the apparatus.

There has thus been described a novel item stackerhopper apparatusincluding means for directing items at high speed into a stacker area bymeans of the so-called Bernoulli effect whereby the items are caused tohug a contact guide plate and glide along on a thin film of airtherebetween during their entry into the stacker-hopper therebycontrolling the item movement while simultane ously reducing to aminimum the free flight condition of the item. The higher the velocityof the air stream along wall member 14 the lower the pressure betweenthe item and the guide plate 14 and thus the greater is the force Fwhich tends to hold or push the items in a direction toward the surfaceof the wall 14 over which the air is flowing.

By virtue of the foregoing the item is assured of being within theso-called target area, i.e., between the rollers 64-66 and the laststacked item so that it cannot abut the rear edge of the previouslystacked item. Additionally, as the Bernoulli eflect is cut off when theitem leaves the bite of the pinch rollers, the blast of air from thenozzle 102 in striking the rear end or trailing edge portion of the itemdrives it downwardly toward the stacker follower offectively moving'theitem out of the path of the next incoming item and avoiding any rear-endcollisions.

What isclaimed is: p

,- 1. Item handling and stacking apparatus comprising:

(a) means forming a stacking area into which items are directed at highspeed,

; (b) means for'driving items into said stacking area,

(c) means adjacent to said driving means for directing a stream of airat high velocity at an acute angle relative to said items into saidstacking area,

((1) rigid, stationary guiding means adjacent to said driving meansextending from said driving means into said stacking area adjacent tosaid air directing means and operably associated therewith so thatexiting high velocity air is caused to strike each item at an acuteangle relative to the surface of such item effective to induce aBernoulli effect between said guiding means and said item whereby apressure differential is created between said guiding means and saiditem effective to produce a thin film of air between said item and saidguiding means so as to cause said item to move on the thin film of airmoving along the surface of said guiding means in close proximitythereto until the item is beyond said driving means whereupon said airdirecting means is effective to cause said high velocity air to strikethe trailing edge of said item and thereby to deflect the trailing edgeof said item through an angle relative to said guiding means moving saidtrailing edge out of the path of the next succeeding incoming item, and

(e) rotatable means having portions intermittently engageable with saiditems as said means is rotated, located adjacent a terminal portion ofsaid guiding means in said stacking area operably associated with saidrigid guiding means for aligning and registering said items as they aredirected thereinto at high speed.

2. Item handling and stacking apparatus comprising:

(a) means providing a collection area into which items may be receivedand stacked in a desired serial consecutive order,

(b) a plurality of rotatable means for entraining and moving itemsserially one at a time at high speed into said area,

(c) a rigid stationary guidance means extending angularly away from saidmoving means and terminating in said collection area,

((1) a high pressure nozzle acutely angularly oriented relative to saidguidance means adjacent to said guidance means for expelling air at ahigh velocity toward saidjcollection area so as to create a pressuredifferential relative to the atmosphere between said guidance means andan item being moved into the stacking area for producing a thin film ofair between the item and the guidance means and effective to cause saiditems to move on said fihn in a straight line path along said guidancemeans toward said stacking area,

(e) a back-up plate in said stacking area operably associated with theterminal portion of said guidance means effective to cause the trailingedge of each item to be deflected angularly out of the path of movementof succeeding items entering said stacking area, and

(f) a plurality of beater rollers including projecting portionsintermittently engageable with said items as said rollers are moved,located adjacent a terminal portion of said rigid guidance means in saidcollection area operably associated with said last named means and saidrigid guidance means for edge aligning and stacking one item after theother in registration.

3. Item handling and stacking apparatus comprising:

(a) means providing a stacking area into which items may be received andstacked in a desired order,

(b) a plurality of drive rollers,

- (c) a plurality of driven rollers operably associated with said driverollers for entraining items therebetween effective so as to move theitems serially one at a time at high speed into said stacking area,

(d) a plurality of hexagonal beater rollers in said stacker areaengageable with said items for slowing the entering speed of the itemsand moving them to a terminal stop in edge aligned condition,

(e) an angled guide plate forming a planar surface extending from saiddrive rollers to said stop,

- (f) a fluid outlet in said plate adjacent to said drive rollersincluding means operably associated therewith for inducing a pressuredifferential between said guide plate and the item being stackedproviding a thin film of air adjacent to said guide plate effective tocause said items to move in a straight line path along said surface inclose proximity thereto into said stacking area, and

(g) means operably associated with said beater rollers for deflectingthe trailing edge of each item angularly out of the path of movement ofsucceeding items entering said stacking area.

4. Item handling and stacking apparatus comprising:

(a) means forming a stacking area into which items are directed at highspeed in serial consecutive order,

(b) means for driving said items into said stacking area,

(c) means adjacent said driving means for directing a stream of air athigh velocity at an angle relative to each item into said stacking area,

((1) rigid, stationary guiding means through which said driving meansprojects to engage said items extending from said driving means intosaid stacking area adjacent to said air directing means and operablyassociated therewith effective to induce a Bernoulli effect between saiditem and said guiding means whereby a pressure differential relative tothe atmosphere is created effective to produce a thin film of air alongthe surface of said guiding means facing said item whereby said item iscaused to move on said thin film of air along the surface of saidguiding means in close proximity thereto until the item is beyond saidair directing means whereupon the high velocity air from said airdirecting means is directed against the trailing edge of said item andthus is effective to deflect the trailing edge of said item through anangle relative to said guiding means moving said trailing edge out ofthe path of the next suceeding incoming item, and

(e) beater roller members adjacent said guiding means and projectingpartially therethrough into said stacking area and provided with aplurality of projections intermittently engageable with each item assaid beater roller members are rotated for applying suitable pressure tothe stacked items to cause the incoming items to be slowed and moved toa terminal position and stopped.

5. Item handling and stacking apparatus comprising:

(a) means forming a stacking area into which items are directed at highspeed in serial consecutive order,

(b) a plurality of drive roller means for driving items into saidstacking area,

(0) a high pressure chamber provided with an elongated hollow boretherethrough effectively forming an integral angled nozzle adjacent tosaid driving means for directing a stream of air at high velocityangularly away therefrom relative to each item and into said stackingarea,

(d) a rigid, stationary angled guide plate through which said drivemeans project to engage said items extending from said drive means intosaid stacking area adjacent to said air directing means and throughwhich high pressure air is angularly discharged between said driverollers toward said stacking area,

(e) pivotal idler roller means operably associated with said drive meansfor entraining and moving said said directing means deflects thetrailing edge of said item through an angle relative to said guidingmeans effectively moving said trailing edge out of the path of the nextsucceeding incoming item, and

(g) beater roller means including a plurality of projecting portionsintermittently engageable with portions of each item as said beaterroller meansare -ro- References Cited UNITED STATES PATENTS itemstherebetween 3,054,6I3 9/ 1962 Forrester 27174 X (f) said air directinineanso enin outwardl through 31O1942 8/1963 Zyber 271-68 g P g Y3,224,761 12/1965 Meyer-Jagenberg 27168 the surface of said guide plateand being efiective to induce a Bernoulli eifect between an incomingitem 20 and said angled guide plate creating a pressure differentialbetween said guide plate and said item providing a thin film of airclose to and along the surface of said guide plate so that said item iscaused to move along said film until the item is beyond said airdirecting means whereupon the issuing air from OTHER REFERENCES IBMBulletin, December 1963, vol. 6, No. 7, (2 pages), pages 20-21.

2 ROBERT B. REEVES, Primary Examiner.

N. L. STACK, Assistant Examiner.

1. ITEM HANDLING AND STACKING APPARATUS COMPRISING: (A) MEANS FORMING ASTACKING AREA INTO WHICH ITEMS ARE DIRECTED AT HIGH SPEED, (B) MEANS FORDRIVING ITEMS INTO SAID STACKING AREA, (C) MEANS ADJACENT TO SAIDDRIVING MEANS FOR DIRECTING A STREAM OF AIR AT HIGH VELOCITY AT AN ACUTEANGEL RELATIVE TO SAID ITEMS INTO SAID STACKING AREA, (D) RIGID,STATIONARY GUIDING MEANS ADJACENT TO SAID DRIVING MEANS EXTENDING FROMSAID DRIVING MEANS INTO SAID STACKING AREA ADJACENT TO SAID AIRDIRECTING MEANS AND OPERABLY ASSOCIATED THEREWITH SO THAT EXITING HIGHVELOCITY AIR IS CAUSED TO STRIKE EACH ITEM AT AN ACUTE ANGLE RELATIVE TOTHE SURFACE OF SUCH ITEM EFFECTIVE TO INDUCE A BERNOULLI EFFECT BETWEENSAID GUIDING MEANS AND SAID ITEM WHEREBY A PRESSURE DIFFERENTIAL ISCREATED BETWEEN SAID GUIDING MEANS AND SAID ITEM EFFECTIVE TO PRODUCE ATHIN FILM OF AIR BETWEEN SAID ITEM AND SAID GUIDING MEANS SO AS TO CAUSESAID ITEM TO MOVE ON THE THIN FILM OF AIR MOVING ALONG THE SURFACE OFSAID GUIDING MEANS IN CLOSE PROXIMITY THERETO UNTIL THE ITEM IS BEYONDSAID DRIVING MEANS WHEREUPON SAID AIR DIRECTING MEANS IS EFFECTIVE TOCAUSE SAID HIGH VELOCITY AIR TO STRIKE THE TRAILING EDGE OF SAID ITEMAND THEREBY TO DEFLECT THE TRAILING EDGE OF SAID ITEM THROUGH AN ANGLERELATIVE TO SAID GUIDING MEANS MOVING SAID TRAILING EDGE OUT OF THE PATHOF THE NEXT SUCCEEDING INCOMING ITEM, AND (E) ROTATABLE MEANS HAVINGPORTIONS INTERMITTENTLY ENGAGEABLE WITH SAID ITEMS AS SAID MEANS ISROTATED, LOCATED ADJACENT A TERMINAL PORTION OF SAID GUIDING MEANS INSAID STACKING AREA OPERABLY ASSOCIATED WITH SAID RIGID GUIDING MEANS FORALIGNING AND REGISTERING SAID ITEMS AS THEY ARE DIRECTED THEREINTO ATHIGH SPEED.